Deflection yoke holding device

ABSTRACT

A deflection yoke holder device for holding a deflection yoke on an attachment for a color cathode ray tube so as to move a neck of the deflection yoke by sliding mutual spherical surfaces, whereby a convergence deviation is corrected.

United States Patent [191 Ishii et al.

DEFLECTION YOKE HOLDING DEVICE Inventors: Hirokazu lshii; Katsumi Nakata, both of Nagaoka-Kyoshi, Japan Assignee: Mitsubishi Denki Kabushiki Kaisha,

Tokyo, Japan Filed: Sept. 24, 1974 Appl. No.: 508,735

US. Cl 335/210; 178/181 Int. Cl. H01F 7/00 Field of Search 335/210, 213; 313/75, 409;

References Cited UNITED STATES PATENTS 10/1968 McLeod et a]. 335/210 X NOV. 18, 1975 3,602,853 8/1971 Cummings et al. 178/781 X 3,629,751 12/1971 Massa 335/210 3,657,674 4/1972 Goldammer 3,697,909 lO/l972 Christensen et al. 335/210 Primary ExaminerG. Harris Attorney, Agent, or Firm-Oblon, Fisher, Spivak, McClelland & Maier [57] ABSTRACT A deflection yoke holder device for holding a deflection yoke on an attachment for a color cathode ray tube so as to move a neck of the deflection yoke by sliding mutual spherical surfaces, whereby a convergence deviation is corrected.

4 Claims, 2 Drawing Figures U.S. Patent Nov. 18, 1975 FIG.

DEFLECTION YOK E HOLDING DEVICE BACKGROUND OF THE INVENTION for a color TV receiver, the horizontal and vertical magnetic fields of the deflection yoke are substantially parallel magnetic fields and the three beams are respectively predeflected by synchronizing deflection with the horizontal period and the vertical period separately, whereby the three beams coincide in all of the picture elements.

In this case, as the magnetic fields are substantially parallel and a device for correcting preliminary deflection is provided, it is not a serious problem if a certain deviation exists between the axis of the electron gun of the cathode tube and the axis of the deflection yoke.

However, in a cathode ray tube wherein the three electron guns are disposed on one plane, the horizontal magnetic field should be a point magnetic field and the vertical magnetic field should be'a cylindrical magnetic field for providing the deflection magnetic field.

Accordingly, the position of dependency of the magnetic field is quite high in comparison with that of the parallel magnetic field configuration. When the axis of the cathode ray tube is not coincident with the axis of the deflection yoke, a large convergence deviation results. The convergence deviation can be corrected by moving the deflection yoke in parallel so as to make both of the axes coincide. However, the inner diameter of the deflection yoke must be sufficiently larger than the outer diameter of the neck of the cathode ray tube to permit such movement. If the inner-diameter of the deflection yoke is large, however, the deflection sensitivity is decreased and the consumption of power and the cost of receiver are disadvantageously increased.

An effect similar to such parallel movement can be obtained, however, by fixing the rear part of the deflection yoke and moving the front part of the deflection yoke, in order to overcome the mentioned disadvantage. In this case, the deflection sensitivity is not reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a deflection yoke holding device which can easily correct a convergence deviation.

It is another object of the invention to provide a deflection yoke holding device which can move the deflection yoke with high accuracy about a center.

The foregoing and other objects of the present invention have been attained by providing a deflection yoke holding device which includes a first holding member having a cylindrical part, one end of which is fixed to an outer suface of a color cathode ray tube; a second holding member having a spherical surface which is fixed to a deflection yoke; and a third holding member having a sliding part which slide along with the cylindrical part of the first holding member, and having a spherical surface which is plied on the spherical surface of the second holding member; whereby the spherical surface of the second holding member is guided on the spherical 2 surface of the third holding member, and the deflection yoke can be moved about the center.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is an exploded view of one embodiment of the deflection yoke holding device according to the present invention; and

FIG. 2 is a sectional view of the assembled embodiment. 7

.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 which illustrates an expansional view of the deflection yoke holding device of the invention, wherein an outer attachment of a cathode ray tube 1 includes a funnel la, a neck lb and a faceplate (not shown in the drawing). A deflection yoke 2 is fitted to the neck lb of the attachment 1. A funnel ring 3 includes a joint part 3a for connecting to the outer surface of the funnel la and a cylindrical part 3b for surrounding the meck lb.

A pair of elongated holes 30 are formed on the cylindrical part 3b. A slider 4 includes a cylindrical part 4a for engagement with the cylindrical part 3b of the funnel ring 3 and a spherical surface 4b. A pair of screw holes 40 are formed on the cylindrical part 4a and a pair of elliptical holes 4d are formed on the spherical surface 4b.

A holder 5 includes a spherical surface 5a for engagement with the spherical surface 4b of the slider 4 and a cylindrical part 5b for fixing the deflection yoke 2. A pair of screw holes 50, 5d are formed on the spherical part 5a and the cylindrical part 5b, respectively. FIG. 2 is a sectional view of the assembly of the parts, wherein the funnel ring 3 is bonded to the funnel la with a bonding agent, and the holder 5 is screwed on the deflection yoke 2 at the cylindrical part 5b.

The cylindrical part 4a of the slider 4 is fitted to the cylindrical part 3b of the funnel ring 3 and the spherical part 4b is slidably mounted on the spherical part 5a of the holder 5. These parts are fastened by the screws having heads 6a and 7a and nuts 6b and 7b at the screw hole 40 and elongated hole 3c, as well as at the eliptical hole 4d and screw hole 5c. The rear end 2a of the deflection yoke 2 is sized for fitting the neck lb without a gap and has elasticity. A vertical deflection coil 2b and a horizontal deflection coil 2c are then equipped.

In the deflection yoke holding device, the deflection yoke 2 can be moved in the forward or reverse direction by sliding the slider 4 along the elongated hole 3c of the funnel ring 3, whereby fine adjustment of the color cathode ray tube is rendered possible.

As the spherical surface 4b of the slider 4 is plied on the spherical surface 5a of the holder 5, the holder 5 can be freely moved within the range of the elliptical holes 4d of the slider 4, about a center of the rear end 2a of the deflection yoke 2, whereby convergence deviation of the color cathode ray tube can be corrected.

In this case, the rear end 2a of the deflection yoke 2 is not moved in the forward or reverse direction, whereby accidental purity deviation is not created.

As stated above, in accordance with the invention, it is possible to provide a deflection yoke holding device for moving the deflection yoke about a center by sliding mutual spherical surfaces, whereby convergence deviation can be corrected by a simple operation.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A deflection yoke device comprising: a first holding member having a cylindricalpart, one end of which is fixed to an outer surface of a color cathode ray tube; a second holding member having a spherical surface which is fixed to a deflection yoke; and a third holding member having a cylindrical part which is capable of matingly sliding along said cylindrical part ofsaid first holding member, and having a spherical surface which is plied on and mates with said spherical surface of said second holding member;

whereby said spherical surface of said second holding member is guided on said sphericalsurface of said third holding member so as to permit said deflection yoke to be rotated about its central axis and said cylindrical part of said third holding member is guided upon said cylindrical part of said first holding member so as to permit said deflection yoke to v be moved in a direction parallel to said axis.

2. The deflection yoke holding device according to claim 1, wherein one end of said deflection yoke is fixed on said second holding member and the other end of said deflection yoke is elastically held on the outer attachment of said color cathode ray tube.

3. The deflection yoke holding device according to claim 1, wherein at least one elliptical hole is formed on said spherical surface of said third holding member and both of said spherical surfaces of said second and third members are plied and connected together by a screw passing through said hole, whereby said deflection yoke can be moved about said axis.

by a screw passing through said elongated hole. 

1. A deflection yoke device comprising: a first holding member having a cylindrical part, one end of which is fixed to an outer surface of a color cathode ray tube; a second holding member having a spherical surface which is fixed to a deflection yoke; and a third holding member having a cylindrical part which is capable of matingly sliding along said cylindrical part of said first holding member, and having a spherical surface which is plied on and mates with said spherical surface of said second holding member; whereby said spherical surface of said second holding member is guided on said spherical surface of said third holding member so as to permit said deflection yoke to be rotated about its central axis and said cylindrical part of said third holding member is guided upon said cylindrical part of said first holding member so as to permit said deflection yoke to be moved in a direction parallel to said axis.
 2. The deflection yoke holding device according to claim 1, wherein one end of said deflection yoke is fixed on said second holding member and the other end of said deflection yoke is elastically held on the outer attachment of said color cathode ray tube.
 3. The deflection yoke holding device according to claim 1, wherein at least one elliptical hole is formed on said spherical surface of said third holding member and both of said spherical surfaces of said second and third members are plied and connected together by a screw passing through said hole, whereby said deflection yoke can be moved about said axis.
 4. The deflection yoke holding device according to claim 1, wherein at least one elongated hole in the longitudinal direction is formed on said cylindrical part of said first holding member and said third holding member is slidably connected to said first holding member by a screw passing through said elongated hole. 